Adjusted gross income, or AGI, is the total reportable income received by a taxpayer during the tax year after “above the line” adjustments, such as IRA contributions, have been made, but before any itemized deductions have been taken. Certain charitable deduction limitations are computed based on a taxpayer's AGI.

The deduction a donor may take in a particular year for a charitable contribution is limited to a percentage of the donor's AGI. The percentage depends on the type of property given and the form of the gift. 30%/50% limitations or 20%/50% limitations may apply.